1. Field of the Invention
This invention relates in general to a delay line for a broadband travelling wave tube which contains spacers and pole shoes which are coaxially arranged relative to an electrically conductive cylinder which contains a helix mounted in the metal cylinder and is fixed in coaxial alignment relative to the metal cylinder by retaining rods and which contains loading rods arranged parallel to the axis of the cylinder and wherein the loading rods or webs are formed in one piece to the inside walls of the electrically conductive cylinder.
2. Description of Related Art
See U.S. Pat. No. 3,397,339, International application WO 80/00049, European 0 121 465 which corresponds to U.S. Pat. No. 4,572,985, French Patent Publication 2 545 645, German DE 32 17 077, French 1,391,842 which corresponds to U.S. Pat. No. 3,203,477 and the publication entitled "Effective Use Of Dispersion Shaping and Broadband Helix TWT Circuits" by Putz and Cascone in I.E.D.M. 1979, Pages 422-424 and the publication entitled "Control of Phase and Gain Deviations In An Octave Bandwidth EHF TWT" by Handy and Puri, IEEDM 1986, Pages 508-511.
A travelling wave tube is described in the article referred to above by Putz and Cascone.
Extremely high demands are made of the dimensional accuracy of the loading webs and of the helix in a travelling wave tube. The spacing distance between the helix and the load webs must be in the range of a few tenths of a millimeter and must be accurate within a few millimeters over a length of, for example, ten centimeters.